Moving Firewood Spreads Invasive Pests
Minnesotans take pride in our natural resources, but our tree-lined streets and forests are at risk. Many pest species, including emerald ash borer, spongy moth, and Asian longhorned beetle, live on or in trees, lumber, and firewood. Moving untreated firewood can spread these invasive pests, which have already killed millions of trees across the U.S. and are harming forests here in Minnesota. Even native pests like wood borers, bark beetles, and carpenter ants can travel in firewood and cause problems for homeowners.
To protect our trees, never move untreated firewood long distances. The only firewood safe to move is MDA-certified, heat-treated firewood, which meets state standards and poses the lowest risk of spreading pests. If you have questions about safe-to-move firewood or suspect a tree has a reportable pest, contact the Minnesota Department of Agriculture’s Report a Pest line at reportapest@state.mn.us or 888-545-6684.
How You Can Protect Our Forests and Tree-line Streets
- Don’t transport firewood. Buy it close to where it will be burned. Locally purchased wood is less likely to contain pests not already in the area. Remember that infested firewood may not show visible symptoms.
- Buy MDA certified, heat-treated firewood. It has been treated to meet state standards and verified by the Minnesota Department of Agriculture as safe to move throughout the state. Certified firewood poses the lowest risk of carrying pests and can be identified by the MDA-certified logo on the label.
- Check the label. Make sure it includes the required information – look for the county where it was harvested. Visit the Minnesota Department of Commerce for more information on firewood labeling laws.
- Follow firewood rules in state parks. If visiting a Minnesota state park, follow the Department of Natural Resources’ firewood guidelines. Burn it quickly. Avoid storing firewood for long periods of time.
If You Have Your Own Firewood
- Burn it close to where it was harvested.
- Use home heating firewood before spring. This helps prevent pests from emerging, as insects and diseases typically attack trees during Minnesota’s growing season.
- Cut new wood in mid to late fall. This reduces the risk of attracting springtime borers.
- Store wood properly. Stack it off the ground and allow for good air circulation to promote drying and reduce pest problems.
- Avoid storing firewood indoors long term.
The Minnesota Department of Agriculture (MDA) regulates invasive pests to prevent their spread through human activities, such as moving firewood. To support this effort, pest quarantines have been established to limit the movement of hardwood firewood.
- It is illegal to transport hardwood firewood out of quarantined counties in Minnesota unless it is MDA certified.
- It is also illegal to bring hardwood firewood into Minnesota from any other state.
- Moving uncertified firewood outside of a regulated area is a violation and may result in fines of up to $7,500 per day, per incident.
To prevent the spread of invasive pests like emerald ash borer (EAB) and spongy moth, strict rules apply to the movement of firewood from quarantined areas.
You can only move firewood out of emerald ash borer (EAB) or spongy moth quarantine areas if all of the following conditions are met:
- Firewood is MDA-certified
- It displays the required MDA certification label
- The bundle is unopened
Firewood cannot be transported out of a quarantine area if:
- The firewood bundle has been opened
- It is not certified as treated
- It does not display the certification shield (MDA or Federal)
Moving untreated firewood is one of the main ways invasive pests and diseases spread. Below are some of the most damaging threats linked to firewood movement:
Emerald Ash Borer (EAB) is a non-native insect that has killed millions of ash trees since it was accidentally introduced to Michigan from China in 2002. This invasive pest continues to spread to other states and Canadian provinces primarily through the movement of infested firewood and nursery stock. It has been detected in Minnesota, and moving firewood could accelerate its spread across the state.
Spongy Moth is one of the most destructive tree pests in the U.S., causing millions of dollars in damage to forests in eastern states. Minnesota’s forests are now at risk. Spongy moth eggs can be unknowingly transported on firewood.
Asian longhorned beetle is a serious threat to hardwood trees such as maple, birch, elm, and ash. It has been found in New York, New Jersey, and Ontario, where quarantines and eradication efforts are ongoing. Although it was detected in Illinois, it has since been eradicated there.
Oak wilt is a fungal disease that kills large numbers of oak trees in Minnesota each year. It spreads when insects carry fungal spores from infected firewood to healthy trees.
Dutch elm disease has devastated Minnesota’s elm population and continues to kill trees every year. Like oak wilt, it spreads when insects move fungal spores from infected firewood to uninfected trees.
